Fiber optic connector with fiber end protection

ABSTRACT

The present disclosure relates to fiber optic connection systems including fiber optic connector having retractable noses for protecting bare fiber ends of ferrule-less connectors. In certain examples, the retractable noses are used in combination with protective shutters. In other examples, the retractable noses can accommodate multiple optical fibers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of provisional application Ser. No.62/092,315, filed Dec. 16, 2014, which is incorporated herein byreference in its entirety.

BACKGROUND

Optical adapters are used to optically couple together optical fibertips of optical connectors. The optical adapters include alignmentstructure that aligns the fiber tips to enable the transfer of opticalsignals therebetween. Optical connectors can be secured to the opticaladapters when received at the ports of the optical adapters.

In certain examples, the optical connectors include ferrule-less opticalconnectors. For example, an example ferrule-less optical connector 300known in the art is shown at FIG. 1. The optical connector 300 includesa connector body 322 having a front mating end 324 and a rear cableterminating end 326. An optical fiber extends forwardly through theconnector body 322 and has a ferrule-less end portion that is accessibleat the front mating end 324 of the connector body 322. The optical fiberis anchored adjacent the rear cable terminating end 326 against axialmovement relative to the connector body 322. When two connectors 300 arecoupled together, the end faces of the ferrule-less end portions abutone another, thereby causing the optical fibers to be forced rearwardlyinto the connector bodies 322 and to buckle/bend within fiber bucklingregions of the connector bodies 322. A shutter 328 moves between closedand open positions. The shutter 328 protects the ferrule-less endportion of the optical fiber from contamination when shut and allowsaccess to the ferrule-less end portion when open.

The connector 300 also includes a latch 330 that engages a catch 355 ofa fiber optic adapter 350 (see FIG. 2). The latch 330 includes aresilient cantilever style latch. When the connectors 300 are insertedwithin the coaxially aligned ports of the adapter 350, the shutters 328of the connectors 300 are retracted, thereby exposing the ferrule-lessends of the optical fibers. Continued insertion causes the ferrule-lessends to enter an optical fiber alignment device. In an example, thefiber alignment device includes funnels leading to a fiber alignmentgroove, and spring-biased balls pressing the fibers into the groove.Other examples of ferrule-less optical connectors and correspondingoptical adapters can be found in U.S. patent application Ser. No.14/377,189, filed Aug. 7, 2014, and titled “Optical Fiber ConnectionSystem Including Optical Fiber Alignment Device,” the disclosure ofwhich is incorporated herein by reference.

Other ferrule-less fiber optic connection systems are disclosed byUnited States Patent Application Publication Nos. US 2013/0216186 and US2014/0072265. The '186 publication discloses a ferrule-less connectorwith a retractable nose piece. The '265 publication discloses analignment system for multi-fiber connectors. Improvements are needed inthe areas of enhanced fiber end protection and fiber alignment in theareas of single fiber and multi-fiber fiber optic connectors.

SUMMARY

Aspects of the present disclosure relate to features for enhancing fiberprotection in ferrule-less connectors. In certain examples, a fiberoptic connector in accordance with the principles of the presentdisclosure can include a shutter for providing initial protection of afiber end, and a retractable nose piece for providing secondaryprotection of the fiber end. In certain examples, the nose piece canalso be configured to assist in directing the fiber end into acorresponding alignment feature of a fiber optic adapter. In certainexamples, the shutter and the nose piece are both automatically openedas the fiber optic connector is inserted within a corresponding fiberoptic adapter. In certain examples, the shutter can include a latch thatretains the shutter in a closed position until the fiber optic connectoris inserted within the corresponding fiber optic adapter.

Another aspect of the present disclosure relates to a multi-fiber,ferrule-less connector having a retractable nose piece for protectingend portions of optical fibers of the fiber optic connector. In certainexamples, the nose piece can assist in registering the end portions ofthe optical fibers with alignment features of a corresponding fiberoptic adapter. In certain examples, the fiber optic adapter can includean array of V-grooves that receive the end portions of the opticalfibers.

A further aspect of the present disclosure relates to a fiber opticconnector including a connector body having a front end and an oppositerear end. The connector body defines a longitudinal axis that extendsthrough the connector body in an orientation that extends from the frontend to the rear end of the connector body. An optical fiber extendsthrough the connector body from the rear end to the front end. Theoptical fiber has a fiber end that is accessible at the front end of theconnector body. The fiber optic connector also includes a nose piecemounted at the front end of the connector body. The nose piece defines afiber passage through which the optical fiber extends. The nose piece ismovable along the longitudinal axis between an extended position where afront end portion of the optical fiber is protected within the fiberpassage and a retracted position where the front end portion of theoptical fiber projects forwardly beyond the nose piece. The fiber opticconnector further includes a shutter mounted at the front end of theconnector body. The shutter is movable between a first position wherethe shutter covers the nose piece and a second position where the nosepiece is exposed. The nose piece provides protection to the front endportion of the optical fiber in the event the shutter is opened prior toinsertion within a fiber optic adapter. Additionally, the nose piece canassist in registering the front end portion of the optical fiber with acorresponding alignment feature of the fiber optic adapter.

Another aspect of the present disclosure relates to a fiber opticconnector including a connector body having a front end and an oppositerear end. The connector body defines a longitudinal axis that extendsthrough the connector body in an orientation that extends from the frontend to the rear end of the connector body. A plurality of optical fibersextend through the connector body from the rear end to the front end.The optical fibers have fiber ends accessible at the front end of theconnector body. The fiber optic connector also includes a nose piecemounted at the front end of the connector body. The nose piece defines aplurality of fiber passages through which the optical fibers extend. Thenose piece is movable along the longitudinal axis between an extendedposition where front end portions of the optical fibers are protectedwithin the fiber passages and a retracted position where the front endportions of the optical fibers project forwardly beyond the nose piece.

A variety of additional inventive aspects will be set forth in thedescription that follows. The inventive aspects can relate to individualfeatures and to combinations of features. It is to be understood thatboth the forgoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the broad inventive concepts upon which the embodiments disclosedherein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the description, illustrate several aspects of the presentdisclosure. A brief description of the drawings is as follows:

FIG. 1 illustrates a prior art ferrule-less fiber optic connector;

FIG. 2 illustrates a prior art fiber optic adapter compatible with theferrule-less fiber optic connector of FIG. 1;

FIG. 3 is a cross-sectional view showing a ferrule-less fiber opticconnector in accordance with the principles of the present disclosure,the fiber optic connector is shown with a shutter in a closed positionand a nose piece in an extended position;

FIG. 4 illustrates the ferrule-less fiber optic connector of FIG. 3 withthe shutter in an open position and the nose piece in a retractedposition;

FIG. 5 illustrates the ferrule-less fiber optic connector of FIGS. 3 and4 in the process of being inserted into a mating fiber optic adapter;

FIG. 6 illustrates the ferrule-less fiber optic connector of FIGS. 3 and4 fully inserted within the mating fiber optic adapter;

FIG. 7 is a perspective view illustrating a multi-fiber, ferrule-lessconnector in accordance with the principles of the present disclosure, anose-piece of the fiber optic connector is shown in an extendedorientation;

FIG. 8 is a cross-sectional view of the multi-fiber, ferrule-lessconnector of FIG. 7;

FIG. 9 illustrates the multi-fiber, ferrule-less connector of FIG. 7with the nose piece in a retracted orientation;

FIG. 10 is a cross-sectional view of the multi-fiber, ferrule-lessconnector of FIG. 9;

FIG. 11 illustrates a multi-fiber, ferrule-less fiber optic connectionsystem in accordance with the principles of the present disclosure;

FIG. 12 is another view of the fiber optic connection system of FIG. 11;

FIG. 13 is an exploded view of the fiber optic connection system ofFIGS. 11 and 12;

FIG. 14 is a rear, perspective view of a multi-fiber connector of thefiber optic connection system of FIGS. 11 and 12;

FIG. 15 is an end view of a port of a fiber optic adapter of the fiberoptic connection system of FIGS. 11 and 12;

FIG. 16 is a cross-sectional view of the fiber optic connection systemof FIGS. 11 and 12 in a partially connected state (i.e., the fiber opticconnector is partially inserted within the port of the correspondingfiber optic adapter);

FIG. 17 is a cross-sectional view of the fiber optic connection systemof FIGS. 11 and 12 in a fully connected state (i.e., the fiber opticconnector is partially inserted within the port of the correspondingfiber optic adapter);

FIG. 18 is a cross-sectional view taken along section line 18-18 of FIG.17 showing a fiber alignment tray stack that forms a fiber alignmentfeature of the fiber optic adapter;

FIG. 19 is a cross-sectional view taken along section line 19-19 of FIG.18 showing cantilever springs that oppose and extend along V-grooves ofthe fiber alignment feature an that function to bias/hold optical fibersin contact with angled alignment surfaces of the v-grooves;

FIG. 20 is an isolated, exploded view of one of the fiber alignmenttrays and a biasing layer of the fiber alignment tray stack;

FIG. 21 shows the biasing layer of FIG. 20 mounted on its correspondingfiber alignment tray;

FIG. 22 is an enlarged view of a fiber management and anchoring traystack of the multi-fiber connector depicted at FIGS. 16 and 17; and

FIGS. 23-26 are further views showing fiber management trays of the traystack of FIG. 22.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary aspects of the presentdisclosure that are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

Aspects of the present disclosure relate to ferrule-less fiber opticconnectors. As used herein, a ferrule-less fiber optic connector is afiber optic connector that does not have a ferrule bonded or otherwiseaffixed to an end portion of an optical fiber of the fiber opticconnector. Structures are disclosed herein to provide enhanced fiberprotection to end portions of optical fibers. Example structures caninclude shutters and/or retractable nose pieces.

FIGS. 3 and 4 illustrate an example fiber optic connector 20 inaccordance with the principles of the present disclosure. The fiberoptic connector 20 is depicted as a ferrule-less fiber optic connector.The fiber optic connector 20 includes a connector body 22 having a frontend 24 and an opposite rear end 26. The connector body 22 defines alongitudinal axis 28 that extends through the connector body 22 in anorientation that extends from the front end 24 to the rear end 26 of theconnector body 22. An optical fiber 30 extends through the connectorbody 22 from the rear end 26 to the front end 24. The optical fiber 30has a fiber end 32 accessible at the front end 24 of the connector body22. The fiber optic connector 20 also includes a nose piece 34 mountedat the front end 24 of the connector body 22. The nose piece 34 definesa fiber passage 36 through which the optical fiber 30 extends. The nosepiece is movable along the longitudinal axis 28 between an extendedposition (see FIG. 3) where a front end portion 38 of the optical fiber30 is protected within the fiber passage 36 and a retracted position(see FIG. 4) where the front end portion 38 of the optical fiber 30projects forwardly beyond the nose piece 34. The fiber optic connector20 further includes a shutter 40 mounted at the front end 24 of theconnector body 22. The shutter is movable between a first position(e.g., a closed position as shown at FIG. 3) where the shutter 40 coversthe nose piece 34 and a second position (e.g., open position as shown atFIG. 4) where the nose piece 34 is exposed.

In certain examples, the fiber optic connector 20 can include a spring42 for biasing the nose piece 34 toward the extended position. Incertain examples, the nose piece 34 retracts back into the connectorbody 22 as the nose piece 34 moves from the extended position toward theretracted position. In certain examples, the shutter 40 is configured topivot relative to the connector body 22 as the shutter moves between theopen and closed positions. In certain examples, the fiber opticconnector 20 can include a latch for retaining the shutter 40 in theclosed position. In certain examples, the latch can be released when thefiber optic connector 20 is inserted within a mating fiber optic adapterthereby allowing the shutter 40 to be moved between the closed and openpositions. In certain examples, relative movement is permitted betweenthe nose piece 34 and the optical fiber 30 so that the nose piece 34 canslide relative to the optical fiber 30. In certain example, the fiberoptic connector 20 includes a fiber anchoring region 41 near the rearend of the connector body 22 where the optical fiber 30 is fixed inposition relative to the connector body 22 thereby preventing relativeaxial movement between the fiber 30 and the connector body 22 at theanchoring location 41. In certain examples, a fiber buckling region 43is provided in the connector body 22 between the anchoring region 41 andthe end portion 38 of the optical fiber 30. The buckling region allowsthe fiber to buckle (i.e., bend, flex) within the connector body 22 whenan optical connection is being made.

FIGS. 5 and 6 show an example fiber optic adapter 50 compatible with thefiber optic connector 20. It will be appreciated that the fiber opticconnector 50 is configured for coupling two of the fiber opticconnectors 20 together such that optical signals can be conveyed betweenthe optical fibers of the coupled fiber optic connectors 20. The fiberoptic adapter 50 can have an alignment feature 52 for receiving andcoaxially aligning the front end portions 38 of the optical fibers ofthe coupled fiber optic connectors 20. In certain examples, thealignment feature 52 can include an alignment passage such as a V-groove53. In certain examples, the alignment feature 52 can include a biasingstructure such as a spring-loaded component that presses the front endportions 38 of the optical fibers 30 into the alignment passage. Asdepicted, the spring-loaded components can include members 55 (e.g.,balls, rods, or other structures) spring-biased toward fiber alignmentsurfaces (e.g., surfaces defining a v-groove) of the alignment passage.

In certain examples, fiber optic adapter 50 can include opposite firstand second adapter ports 54, 56 with the alignment feature 52 disposedtherein between. The first and second adapter ports 54, 56 can beconfigured for respectively receiving fiber optic connectors 20 desiredto be coupled together. It will be appreciated that the shutters 40 ofthe fiber optic connectors 20 move from the closed position to the openposition as the fiber optic connectors 20 are inserted into theirrespective ports 54, 56. Similarly, the nose pieces 34 of the fiberoptic connectors 20 move from the extended positions to the retractedpositions as the fiber optic connectors 20 are inserted into theirrespective ports 54, 56. When the nose pieces 34 retract, the front endportions 38 of the optical fibers 30 protrude forwardly beyond the nosepieces 34 and thereby can be inserted into the alignment passage (e.g.,groove) of the alignment feature 52. In certain examples, the shutters40 move at least partially toward the open positions prior to the nosepieces 34 beginning to move from the extended positions toward theretracted positions. In certain examples, the fiber passages 36 of thenose pieces 34 align with the alignment passages of the alignmentfeature 52 to assist in guiding the front end portions 38 into thealignment groove of the alignment feature 52 as the nose pieces 34retract.

As described above, in certain examples, the alignment passage isdefined by an open-sided groove such as a V-groove. Additionally, incertain examples, resilient structures are provided for biasing thefront end portions 38 of the optical fibers 30 into the open sidedgrooves. In certain examples, the resilient structures can includestructures such as spring-biased balls, flexible cantilevers and otherstructures.

In certain examples, the alignment passage is defined by the fiberalignment feature 52 of the fiber optic adapter 50. In certain examples,the fiber alignment feature 52 can include first and second oppositeends 58, 59. In certain examples, the nose pieces 34 of the fiber opticconnectors 20 inserted within the adapter ports 54, 56 respectively abutagainst the first and second ends 58, 59 of the fiber alignment feature52 when the fiber optic connectors 20 are inserted into the first andsecond adapter ports 54, 56 thereby causing the nose pieces 34 toretract.

FIGS. 7-10 illustrate another fiber optic connector 120 in accordancewith the principles of the present disclosure. In the depicted example,fiber optic connector 120 is a ferrule-less, multi-fiber fiber opticconnector.

Referring still to FIGS. 7-10, the fiber optic connector 120 includes aconnector body 122 having a front end 124 and an opposite rear end 126.In certain examples, a fiber optic cable can be coupled to the fiberoptic connector 120 adjacent the rear end 126. The connector body 122defines a longitudinal axis 128 that extends through the connector body122 in an orientation that extends from the front end 124 to the rearend 126 of the connector body 122. A plurality of optical fibers 130extend through the connector body 122 from the rear end 126 to the frontend 124. The optical fibers 130 have fiber ends 132 accessible at thefront end 124 of the connector body 122. The fiber optic connector 120also includes a nose piece 134 mounted at the front end 124 of theconnector body 122. The nose piece 134 defines a plurality of fiberpassages 136 through which the optical fibers 130 extend. It will beappreciated that the optical fibers 130 are slidable within the fiberpassages 136 such that relative movement is permitted in an orientationthat extends along the longitudinal axis 128. The nose piece 134 ismovable along the longitudinal axis 128 relative to the connector body122 between an extended position (see FIGS. 7 and 8) where front endportions 138 of the optical fibers 130 are protected within the fiberpassages 136 and a retracted position (see FIGS. 9 and 10) where thefront end portions 138 of the optical fibers 130 project forwardlybeyond the nose piece 134. It will be appreciated that when the nosepiece 134 is in the retracted position, the front end portions 138 ofthe optical fibers 130 project forwardly beyond the nose piece 134 adistance sufficiently long to allow the front end portions 138 to beinserted within a suitable alignment structure. In certain examples, analignment structure can be provided within a fiber optic adapterconfigured for coupling two of the fiber optic connectors 120 together.In another example, a direct connection may be made between mating fiberoptic connectors without the use of an intermediate adapter. In such anexample, the front end portions 138 of the fibers of one fiber opticconnector may fit within alignment grooves defined by a mating fiberoptic connector.

Referring to FIGS. 8 and 10, the fiber optic connector 120 can include aspring 142 for biasing the nose piece 134 toward the extendedorientation. Additionally, as shown at FIGS. 7 and 9, registrationelements can be provided on the nose piece 134 to assist in providingregistration between two fiber optic connectors desired to be coupledtogether. In certain examples, the registration structures can includealignment pins 143 and/or alignment openings 144. In certain examples,the alignment pins 143 can fit within alignment openings of acorresponding fiber optic connector or a corresponding fiber opticadapter, and the alignment openings 144 can receive alignment pins of amating fiber optic connector or a mating fiber optic adapter.

In certain examples, fiber optic connector 120 is a robust, hardenedfiber optic connector suitable for outdoor use. In certain examples,fiber optic connector 120 can include structure for providingenvironmental sealing when inserted within the port of a correspondingfiber optic adapter or when coupled to a mating fiber optic connector.For example, as shown at FIGS. 8 and 10, the fiber optic connector 20can include a sealing element such as an annular sealing ring 145 (e.g.,an O-ring) that mounts within an annular groove that extends about theperimeter of the connector body 122. In certain examples, a robustcoupling element can be provided for securing the connector body 22within the corresponding port of a fiber optic adapter or to a matingfiber optic connector. For example, the robust coupling element caninclude a twist-to-lock coupling element such as a threaded couplingelement 147 (e.g., an exteriorly threaded nut or an interiorly threadedsleeve) or a bayonet-style coupling element.

It will be appreciated that the connector body 122 can also include oneor more keying features for ensuring that the fiber optic connector isinserted into a corresponding port of a fiber optic adapter or matingfiber optic connector at a predetermined rotational orientation. Examplekeying structures can include rails, projections, grooves or otherstructures. As depicted, the fiber optic connector 120 is provided witha key in the form of a rail 146 configured to fit within a correspondinggroove defined by a mating adapter or connector port.

FIGS. 11-13 illustrate another multi-fiber fiber optic connector 220 inaccordance with the principles of the present disclosure. The fiberoptic connector 220 includes a connector body 222 having a front end 224and an opposite rear end 226. The connector body 222 defines alongitudinal axis 228 that extends along a length of the connector body222. The rear end 226 of the connector body 224 can be configured tocouple to a fiber optic cable 227. The fiber optic cable 227 can includea jacket 229 containing a plurality of optical fiber ribbons 231. Thefiber optic cable 227 can include reinforcing members 233 (e.g.,reinforcing rods such as epoxy reinforced fiber glass rods or othertypes of reinforcing elements such as Aramid yarn). In certain examples,the reinforcing members 233 can be secured (e.g., bonded, clamped, orotherwise attached) to the connector body 222. In certain examples, thereinforcing members 233 can be secured within openings 235 (see FIG. 14)defined adjacent the rear end 226 of the connector body 222. Asdepicted, the fibers are not shown routed through the fiber opticconnector 220.

Referring to FIG. 13, the connector body 122 has a two-part constructionincluding a main body 237 and a cover 239. The main body 237 and thecover 239 mate together to form the connector body 222. A reinforcingsleeve 241 can be mounted over the connector body 222 after the cover239 and the main body 237 have been mated together. The fiber opticconnector 120 can also include an outer housing 243 that mounts over theconnector body 222. Additionally, the fiber optic connector 220 caninclude a fastening element such as a robust fastening element forsecuring the fiber optic connector 220 to a corresponding fiber opticadapter 245. In certain examples, the fastening element can include atwist-to-lock fastening element such as a bayonet-style fasteningelement or a threaded fastening element. As depicted, the fasteningelement includes an internally threaded sleeve 247 that mates withcorresponding exterior threads 249 provided at one end of a fiber opticadapter 245.

The fiber optic adapter 245 includes a first port 251 that receives thefiber optic connector 222 and an opposite second port 253 adapted toreceive a fiber optic connector desired to be optically coupled to thefiber optic connector 222. In certain examples, the fiber optic adapter245 can be mounted within a hole in an enclosure or panel and can havesuitable sealing structure for providing an environmental seal with thepanel or enclosure.

Referring to FIG. 13, fiber optic connector 220 can include a nose piece234 that is movable along the longitudinal axis 228 relative to theconnector body 222 between an extended position and a retractedposition. The nose piece 234 can define a plurality of fiber passages236 that receive front end portions of optical fibers corresponding tothe optical fiber ribbons 231. In certain examples, the front endportions can be bare glass portions of the optical fibers including onlythe fiber cores and cladding layers. It will be appreciated that thefront end portions (not shown) of the optical fibers can slide withinthe nose piece 234 as the nose piece 234 is moved between the extendedand retracted positions. When the nose piece 234 is extended, the frontend portions of the optical fibers are protected and enclosed within thenose piece 234. When the nose piece 234 is retracted, the front endportions of the optical fibers are exposed thereby allowing the frontend portions to be inserted within a corresponding alignment featureprovided in the fiber optic adapter 245.

In certain examples, the nose piece 234 can be spring-biased toward theextended position by one or more springs 255 positioned within theconnector body 222. In certain examples, the nose piece 134 can includea main body 257 and a front extension 259. The main body 257 can becaptured within an interior of the connector body 222, and the frontextension 259 can extend into a front opening 260 defined at the frontend 224 of the connector body 222. The main body 257 can define flangesthat project outwardly from the front extension 259. In certainexamples, the springs 255 can be positioned on opposite sides of theoptical fibers (e.g., above and below) and can engage a backside of themain body 257 at the flanges. In certain examples, the two-piececonstruction of the connector body 222 facilitates laterally loading thenose piece 234, the springs 255 and other components into the interiorof the connector body 222.

It will be appreciated that the fiber optic connector 220 can alsoinclude structure within the interior of the connector body 220 formanaging and anchoring the optical fibers. In certain examples, thefiber management and anchoring structure can be defined by a stack ofminiature fiber management trays 261 positioned within the connectorbody 222. The fiber management trays 261 can define a separate fiberbuckling passages 262 corresponding to each of the optical fibers. Thestack of fiber management trays 261 can also include a fiber anchoringregion 265 for anchoring the optical fibers relative to the connectorbody 222. It will be appreciated that the fiber buckling passages 264are positioned between the fiber anchoring region 265 and the passages236 in the nose piece 234 for receiving the front end portions of theoptical fibers.

As shown at FIGS. 22-26, the fiber management trays 261 can each includea first side (e.g., a top side as depicted) defining a plurality ofparallel shallow grooves 290 and an opposite second side (e.g., a bottomside as depicted) defining a plurality of deeper grooves 291. When thetrays 261 are stacked, the top and bottom sides of adjacent trays 261oppose one another and interlock or mate with one another to providemechanical registration between the trays 261. The shallow and deepergrooves 291 register within one another and cooperate to define theseparate fiber buckling passages 262. The opposing sides of adjacenttrays 261 also form clamping regions 293 where the spacing between theopposing sides is small enough that the optical fibers are compressedbetween the trays and held in place. The clamping regions 293 can formthe fiber anchoring region 265.

In certain examples, fiber management trays 261 are mounted in fixedrelation relative to the connector body 222, and the nose piece 234 isfree to move forwardly and rearwardly relative to the fiber managementtrays 261. In certain examples, the fiber buckling slots 263 generallyalign with the fiber passages 236 of the nose piece 234.

It will be appreciated that the fiber optic adapter 245 can include aninterior fiber alignment feature 271 for coaxially aligning the opticalfibers of the fiber optic connector 220 with the optical fibers of acorresponding fiber optic connector desired to be coupled to the fiberoptic connector 220 via the fiber optic adapter. In certain examples,the fiber alignment feature 271 includes a stack of fiber alignmenttrays 272 that define an array of alignment grooves (e.g., V-grooves295) for receiving the front end portions of the optical fibers when thefiber optic connector 220 is inserted within the first port 251 and thenose piece 234 is retracted. It will be appreciated that the fiberpassages 236 assist in registering the optical fibers 130 with thealignment grooves 295 defined by the fiber alignment trays 272 (see FIG.19). In certain examples, an end of the fiber alignment feature 271 canfit or mate at least partially within the front end 224 of the connectorbody 222 (e.g., the alignment feature can fit within the front opening260). In this way, the distance the fibers project beyond the front endof the connector body 222 is minimized while still allowing substantiallengths of the optical fibers to be inserted within the fiber alignmentfeature 271 of the fiber optic adapter 245.

The fiber optic adapter 245 can also include alignment projections 275that fit within corresponding alignment openings 277 defined by a frontface of the connector body 222 when the fiber optic connector 220 isinserted within the first port 251 of the fiber optic adapter 245. Themating alignment projections 275 and alignment openings 277 can providean alignment and keying function. Additionally, when the alignmentprojections 275 slide into the alignment openings 277, the alignmentprojections 275 can engage a front side of the main body 257 of the nosepiece 234 thereby causing the nose piece to move from the extendedposition toward the retracted position as the fiber optic connector 220is inserted into the first port 251.

When the fiber optic connector 220 is optically coupled to another fiberoptic connector by the fiber optic adapter 245, the fiber ends of thecoupled fiber optic connectors preferably engage one another. The fiberbuckling slots 263 provide space for allowing the optical fibers 230 toslightly buckle within the connector body 222 as the fiber ends 232contact one another. Thus, the fiber buckling slots 263 provide take-upregions for receiving buckled portions of the fibers when an opticalconnection is made. The buckling of the fibers provides axial loading onthe optical fibers that ensures the end faces of the optical fibersremain in contact with one another. Additionally, the ability to allowthe optic fibers to buckle provides extra tolerance and range of motionthat ensures all of the optical fibers of the interconnected fiber opticconnectors in engagement with one another.

In certain examples, the fiber alignment feature 271 can include rows ofcantilevers 280 for biasing the fiber end portions into the v-grooves295 (see FIGS. 20 and 21). In certain examples, one cantilever 280 isprovided for every two of the v-grooves 295. The cantilevers 280 can bepart of a biasing layer 296 that includes two sets of cantilevers 280with one set of cantilevers 280 a corresponding to the fibers of one ofthe fiber optic connectors received within the fiber optic adapter andthe other set of cantilevers 280 b corresponding to the other fiberoptic connector received within the fiber optic adapter. The biasinglayers 296 can be formed by stamping the cantilevers 280 from plates.The biasing layers 296 can be provided between the fiber alignment trays272 of the alignment tray stack.

Various modifications and alterations of this disclosure will becomeapparent to those skilled in the art without departing from the scopeand spirit of this disclosure, and it should be understood that thescope of this disclosure is not to be unduly limited to the illustrativeexamples set forth herein.

What is claimed is:
 1. A fiber optic connector comprising: a connectorbody having a front end and an opposite rear end, the connector bodydefining a longitudinal axis that extends through the connector body inan orientation that extends from the front end to the rear end of theconnector body; an optical fiber that extends through the connector bodyfrom the rear end to the front end, the optical fiber having a fiber endaccessible at the front end of the connector body; a nose piece mountedat the front end of the connector body, the nose piece defining a fiberpassage through which the optical fiber extends, the nose piece beingmovable along the longitudinal axis between an extended position where afront end portion of the optical fiber is protected within the fiberpassage and a retracted position where the front end portion of theoptical fiber projects forwardly beyond the nose piece; and a shuttermounted at the front end of the connector body, the shutter beingmoveable between a first position where the shutter covers the nosepiece and a second position where the nose piece is exposed.
 2. Thefiber optic connector of claim 1, wherein the nose piece is springbiased toward the extended position, and wherein the nose piece retractsback into the connector body as the nose piece moves from the extendedposition toward the retracted position.
 3. The fiber optic connector ofclaim 2, wherein the shutter pivots relative to the connector body asthe shutter moves between the first and second positions.
 4. The fiberoptic connector of claim 1, wherein the front end portion of the opticalfiber is a bare glass portion that does not have a ferrule securedthereto.
 5. The fiber optic connector of claim 3, further comprising alatch for retaining the shutter in the first position.
 6. A fiber opticconnection system comprising: first and second fiber optic connectorseach including: a connector body having a front end and an opposite rearend, the connector body defining a longitudinal axis that extendsthrough the connector body in an orientation that extends from the frontend to the rear end of the connector body; an optical fiber that extendsthrough the connector body from the rear end to the front end, theoptical fiber having a fiber end accessible at the front end of theconnector body; a nose piece mounted at the front end of the connectorbody, the nose piece defining a fiber passage through which the opticalfiber extends, the nose piece being movable along the longitudinal axisbetween an extended position where a front end portion of the opticalfiber is protected within the fiber passage and a retracted positionwhere the front end portion of the optical fiber projects forwardlybeyond the nose piece; and a shutter mounted at the front end of theconnector body, the shutter being moveable between a first positionwhere the shutter covers the nose piece and a second position where thenose piece is exposed; and an adapter for coupling the first and secondfiber optic connectors together such that optical signals can beconveyed between the optical fibers of the first and second fiber opticconnectors, the adapter having an alignment passage for receiving andco-axially aligning the front end portions of the optical fibers.
 7. Thefiber optic connection system of claim 6, wherein the adapter includesopposite first and second adapter ports for respectively receiving thefirst and second connectors, wherein the shutters move from the firstposition to the second position as the first and second fiber opticconnectors are inserted into their respective first and second ports,and wherein the nose pieces move from the extended positions to theretracted positions as the first and second connectors are inserted intotheir respective first and second ports.
 8. The fiber optic connectionsystem of claim 7, where shutters move at least partially toward thesecond positions prior to the nose pieces beginning to move from theextended positions toward the retracted positions.
 9. The fiber opticconnection system of claim 8, wherein the fiber passages of the nosepieces co-axially align with the alignment passage of the adapter toassist in guiding the front end portions of the optical fibers into thealignment passage.
 10. The fiber optic connection system of claim 9,wherein the alignment passage is defined by an open sided groove, andwherein the adapter includes resilient structures for biasing the frontend portions of the optical fibers into the open sided groove.
 11. Thefiber optic connection system of claim 10, wherein the alignment passageis defined by a fiber alignment structure of the adapter, wherein thefiber alignment structure includes first and second opposite ends, andwherein the nose pieces of the first and second connectors respectivelyabut against the first and second ends of the fiber alignment structurewhen the first and second connectors are inserted into the first andsecond ports.
 12. A fiber optic connector comprising: a connector bodyhaving a front end and an opposite rear end, the connector body defininga longitudinal axis that extends through the connector body in anorientation that extends from the front end to the rear end of theconnector body; a plurality of optical fibers that extend through theconnector body from the rear end to the front end, the optical fibershaving fiber ends accessible at the front end of the connector body; anda nose piece mounted at the front end of the connector body, the nosepiece defining a plurality of fiber passages through which the opticalfibers extend, the nose piece being movable along the longitudinal axisbetween an extended position where front end portions of the opticalfibers are protected within the fiber passages and a retracted positionwhere the front end portions of the optical fibers project forwardlybeyond the nose piece.
 13. The fiber optic connector of claim 12,wherein the fiber optic connector includes a fiber anchoring region foranchoring the optical fibers relative to the connector body, and whereinthe fiber optic connector defines a fiber buckling region between thefiber anchoring region and the front end portions of the optical fibers.14. The fiber optic connector of claim 13, wherein the fiber opticconnector includes a stack of fiber management trays positioned withinthe connector body, the fiber management trays defining a separate fiberbuckling slot corresponding to each of the optical fibers, the fiberanchoring region also being defined within the stack of fiber managementtrays.
 15. The fiber optic connector of claim 14, wherein the nose piecemoves along the longitudinal axis relative to the stack of fibermanagement trays, and wherein the fiber buckling slots align with thefiber passages of the nose piece.
 16. The fiber optic connector of claim12, wherein the fiber optic connector is configured to interface with afiber optic adapter, wherein the fiber optic adapter includes alignmentprojections, wherein the connector body defines alignment openings thatreceive the alignment projections when the fiber optic connector isinserted into the fiber optic adapter, wherein the nose piece hasflanges positioned within the fiber optic connector, and wherein thealignment projections contact the flanges to push the nose piece formthe extend portion to the retracted position as the fiber opticconnector is inserted into the fiber optic adapter.
 17. The fiber opticconnector of claim 16, wherein the fiber optic adapter includes a stackof alignment trays that define an array of v-grooves for receiving thefront end portions of the optical fibers.